The core CSLM facility proposed provides the currently available CSLM facility in Dr. Gage's laboratory to all members of the program and upgrades the facility to permit real time CSLM analysis of cultured cells. CSLM technology permits precise localization of fluorescent or highly reflective material within tissue, within cells in tissue or in cultured cells. CSLM is superior to conventional fluorescent microscopy because it allows the examination of a narrow plane of focus without the interference of out of focus light from above and below the plane of interest and because it can permit the rapid accumulation of digitized images so that brief changes in fluoresence can be detected. Within the program all PIs have proposed experiments which require the use of the CSLM facility for examination of histological tissue sections. These applications include the precise localization of antigens under study, the ability to accurately localize silver grains from autoradiography, the quantification of synaptic counts and sprouting, the stereological assessment of cell number and the ability to visualize the path taken by regenerating axons in vivo. The requested upgrades to the confocal facility will permit PI's to examine dynamic in vitro intracellular events (e.g., ionic concentration changes) occurring when cultured neurons of interest are exposed to factors believed to produce or inhibit neural damage. This approach will allow for the examination of the cellular mechanism of action of treatments investigated on whole animals elsewhere in the grant.